Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Geological Survey and the Department of Interior
Publication_Date: 2012
Title: Airborne geophysical survey: Oquossoc, Maine
Geospatial_Data_Presentation_Form: analog contour map
Online_Linkage: http://mrdata.usgs.gov/magnetic/show-survey.php?id=0494
Description:
Abstract:
Aeromagnetic data were collected along flight lines by instruments in an
aircraft that recorded magnetic-field values and locations. In the earlier
days of surveying, the only way to represent this data was to generate an
analog map with contour lines. This dataset is a representation of the
digitized contour lines either by following the lines or by choosing the
intersection of the contour and flight-line to create a value of the magnetic
field. The values presented are latitude, longitude, and map magnetic-field
values.
Purpose:
Aeromagnetic surveys are used for geophysical prospecting. Some variations in
magnetic measurements are caused by rocks that contain significant amounts of
magnetic minerals (magnetite being the most common). These anomalies reflect
variations in the amount and type of magnetic material and the shape and depth
of the body of rock. The features and patterns of aeromagnetic anomalies can
also be used to delineate details of subsurface geology including the locations
of buried faults and the thickness of surficial sedimentary rocks.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19620825
Ending_Date: 19620825
Currentness_Reference: ground condition
Status:
Progress: complete
Maintenance_and_Update_Frequency: none planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -71.00
East_Bounding_Coordinate: -70.75
North_Bounding_Coordinate: 45.25
South_Bounding_Coordinate: 44.75
Data_Set_G-Polygon:
Data_Set_G-Polygon_Outer_G-Ring:
G-Ring:
-71.00 45.25, -70.75 45.25, -70.75 44.75,
-71.00 44.75, -71.00 45.25
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: geophysical surveys
Theme_Keyword: aeromagnetic data
Theme_Keyword: airborne surveys
Theme_Keyword: magnetic surveys
Theme_Keyword: residual magnetic field
Theme_Keyword: total field
Theme_Keyword: magnetic
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geophysics
Theme_Keyword: geospatial datasets
Theme_Keyword: magnetic field (earth)
Theme_Keyword: aeromagnetic surveying
Theme_Keyword: field monitoring stations
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: United States
Place_Keyword: Maine
Place_Keyword: ME
Place_Keyword: Oquossoc
Place_Keyword: Cupsuptic
Place:
Place_Keyword_Thesaurus: Common Geographic Areas
Place_Keyword: f23007 = Franklin
Place_Keyword: f23017 = Oxford
Access_Constraints: none
Use_Constraints:
none. Acknowledgement of the U.S. Geological Survey would be appreciated
in products derived from these data.
Browse_Graphic:
Browse_Graphic_File_Name: http://mrdata.usgs.gov/geophysics/surveys/geophysics3/ME/me0494.jpg
Browse_Graphic_File_Description: Reduced-size image depicting the data, 736 x 1419 pixels, 92,924 bytes
Browse_Graphic_File_Type: JPEG
Data_Set_Credit:
These USGS employees contributed to reformatting and archiving these data:
Viki Bankey, Pat Hill, Holly Hindle,
Bob Kucks, Sarah Shearer, Esther Castellanous
Cross_Reference:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 1964
Title:
Aeromagnetic map of the Cupsuptic Quadrangle,
Oxford and Franklin counties, Maine
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: U.S. Geological Survey Geophysical Investigations Map
Issue_Identification: GP-477
Publication_Information:
Publication_Place: Denver, CO
Publisher: U.S. Geological Survey
Other_Citation_Details:
by G.R. Boynton and F.P. Gilbert
map scale 1:62,500
Cross_Reference:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 1964
Title:
Aeromagnetic map of the Oquossoc Quadrangle,
Oxford and Franklin counties, Maine
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: U.S. Geological Survey Geophysical Investigations Map
Issue_Identification: GP-478
Publication_Information:
Publication_Place: Denver, CO
Publisher: U.S. Geological Survey
Other_Citation_Details:
by G.R. Boynton and F.P. Gilbert
map scale 1:62,500
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The data shown on the original map have been processed using various
formulas and methods that are not usually documented but that represent
industry standard practices for airborne data reduction. For example,
position is listed as latitude and longitude, but these values were
derived from the raw navigation data depending on the system used.
(see notes under horizontal accuracy). Line numbers were added to
records, and unusable data at flight-line ends were discarded
(as aircraft slowed and turned around). Separate recordings were
correlated by time and assigned to the correct location.
The exact accuracies of these processing steps may not be known. They
are discussed in the sections on attribute or positional accuracies.
Logical_Consistency_Report:
The data on the original map were collected by a single contractor or group
who were responsible for collecting and processing the data.
The data from this survey were collected using the same instruments
(magnetometers, altimeters, navigational systems) throughout
the survey and were collected in a normal length of time with no long
delays between survey beginning and end.
Survey layout specified the conditions and specifications under which
these data were collected. Standard industry practices of the time
were followed in data collection and processing.
Completeness_Report: Data is complete as reasonably digitized from the original map
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Flight Path Recovery
Horizontal position of the survey aircraft used to collect
data were determined by reconciling down-looking photographs
(recorded on continuous-strip film) with topographic maps
and orthophotoquadrangle maps. Fiducial numbers and marks,
impressed on any paper strips that were recording data or
added to magnetic tape records, were included as a function of
time to further reconcile location with instrumentation.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The aircraft vertical position was determined using the
navigational positioning equipment on the aircraft, which
were radar altimeter and barometric altimeter.
Lineage:
Process_Step:
Process_Description:
Conversion of measured values to geographic position and
magnetic values was performed by the processors using
industry standard practices.
Details are found under Horizontal_Position_Accuracy_Report,
and Vertical_Position_Accuracy_Report
Unless noted, conversion processes were not documented.
Products may include some written documentation.
Process_Date: 1962
Process_Step:
Process_Description:
USGS digitized original map to ASCII format.
USGS personnel used the software package Oasis Montaj by
Geosoft, Inc., to read in the ASCII digitized data and create
raster JPEG images.
Process_Date: 2008
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: point
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.0001
Longitude_Resolution: 0.0001
Geographic_Coordinate_Units: decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6,378,206.4
Denominator_of_Flattening_Ratio: 294.98
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Airborne survey specifications
These items are constant for the entire survey
Project number: 0494
Project name: Oquossoc
Survey flown by: U.S. Geological Survey
Survey flown for: U.S. Geological Survey
Approx. no. of line miles: 860
Survey height: 3500 ft
Altitude method: Above sea level
Flight-line spacing: 0.5 mi
Flight-line direction: N-S
Aircraft used: Douglas DC-3
Airport - arrival: Waterville, ME
airport - departure: Waterville, ME
Sensor tow distance: unknown
Magnetometer used: fluxgate
Data recording interval: unknown
Regional field removed: none
Entity_and_Attribute_Detail_Citation:
Nettleton, L.L., 1971, Elementary Gravity and Magnetics for
Geologists and Seismologists: Society of Exploration Geophysicists
Monograph Series No. 1.
Dobrin, M.B., 1976, Introduction to Geophysical Prospecting:
New York, McGraw-Hill Book Company,
Sheriff, R.E., 1984, Encyclopedic dictionary of exploration
geophysics: Tulsa, OK, Society of Exploration Geophysicists.
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Web site administration: U.S Geological Survey
Central Publications Group
Contact_Address:
Address_Type: mailing address
Address:
Central Publications Group
USGS MS 902, Box 25046 DFC
City: Denver
State_or_Province: CO
Postal_Code: 80225-0046
Contact_Voice_Telephone: 303-236-5486
Distribution_Liability:
Although all data published on this website have been used by the USGS,
no warranty, expressed or implied, is made by the USGS as to the
accuracy of the data and related materials. The act of distribution
shall not constitute any such warranty, and no responsibility is
assumed by the USGS in the use of these data or related materials.
Any use of trade, product, or firm names is for descriptive purposes
only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ASCII
Format_Specification:
Each line contains data in the following format,
beginning with line 1 (no header included):
longitude F12.4 Longitude in decimal degrees
latitude F12.4 Latitude in decimal degrees
mag F8.1 Magnetic value represented on map. This is the
total field value with an arbitrary datum removed
Format_Version_Date: 1998
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://crustal.usgs.gov/geophysics/index.html for link to report
Fees: none
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Peter N Schweitzer
Contact_Organization: USGS Eastern Mineral and Environmental Resources Science Center
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing address
Address: 12201 Sunrise Valley Drive
City: Reston
State_or_Province: VA
Postal_Code: 20192-0002
Country: USA
Contact_Voice_Telephone: 703-648-6533
Contact_Facsimile_Telephone: 703-648-6252
Contact_Electronic_Mail_Address: pschweitzer@usgs.gov
Resource_Description: me0494_meta.txt
Distribution_Liability:
This dataset was prepared by an agency of the United States
Government. Neither the United States Government nor any agency
thereof, nor any of their employees, make any warranty, expressed or
implied, or assumes any legal liability or responsibility for the
accuracy, completeness, or usefulness of any information, apparatus,
product, or process disclosed in this report, or represents that its
use would not infringe privately owned rights. Reference therein to
any specific commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not necessarily constitute
or imply its endorsement, recommendation, or favoring by the United
States Government or any agency thereof. Any views and opinions of
authors expressed herein do not necessarily state or reflect those of
the United States Government or any agency thereof.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: CSV
Format_Information_Content: Flight-line airborne magnetic anomaly measurements
File_Decompression_Technique: none
Transfer_Size: 0.059272766113281
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://mrdata.usgs.gov/geophysics/surveys/geophysics3/ME/me0494.txt
Fees: none
Metadata_Reference_Information:
Metadata_Date: 20141205
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USGS Crustal Geophysics and Geochemistry Science Center
Contact_Address:
Address_Type: mailing address
Address:
Magnetic and Gravity Information
U.S. Geological Survey
Box 25046 Mail Stop 964
Denver Federal Center
City: Denver
State_or_Province: CO
Postal_Code: 80225-0046
Contact_Voice_Telephone: 303-236-5652
Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998